General Use:Polycarbonate plastic glasses and dishes are virtually unbreakable under impact.Dishwasher use:Polycarbonate plastic tableware is designed for years of use in both commercial and residential dishwashers for water temperatures up to 150-degrees F. Polycarbonate plastic drinkware and dishes and will not cloud and craze like acrylic glasses unless exposed to excessively high heat.A note for residential users...EnergyStar-rated residential dishwashers feature water heating systems that can far exceed commercial temperatures and damage polycarbonate. Please consult your dishwasher user's guide for a delicate/lower heat cycle to prevent damage to ALL plasticware -- including polycarbonate products.Microwave use:Polycarbonate tableware is microwave reheat-safe -- up to 2 minutes recommended.Scratching and Wear:Polycarbonate plates are not scratch-proof. Polycarbonate plastic dishes are not recommended for heavy use with knives. Melamine Plastic Dishes are ideal for heavy use with knives - see our Plastic Tableware section for several durable Melamine styles.